Piston-cylinder assemblies of the general type under consideration are used predominantly in pneumatic gearshifts, mechatronic units, pneumatic systems and hydraulic systems. The piston-cylinder assembly usually serves the purpose of converting pressures that are applied to a piston into a movement of the piston rod. This movement is used in the different technical fields for controlling and/or for driving machines or machine elements.
In order to make it possible to monitor and/or control the movement of such machines, it is of increased importance to be able to determine the piston stroke that actually takes place and results from the applied pressure. A detection of the position of the piston and/or the piston rod is therefore required.
Conventionally, position detection of the piston or the piston rod is accomplished by means of measuring devices arranged externally on the piston-cylinder assembly that detect the position change of the piston rod by means of various measuring methods, for example inductive measuring methods. This presents several disadvantages. In particular, in installation surroundings that require a small installation space of the piston-cylinder assembly, the known measuring systems cannot be used. The installation space that is often available is not dimensioned sufficiently for this purpose. In particular, the installation dimension of the piston-cylinder assembly in the stroke direction is typically restricted in practice. However, this is exactly the preferred arrangement of the measuring systems in constructions of the type noted above.